BRATTLEBORO — She is either a financially desperate, cold-blooded killer who used insulin as her weapon of choice or a dependable caregiver who was unjustly charged with murder in the mysterious death of an 83-year-old Brattleboro woman.

Those were the two pictures of Jodi LaClaire painted during opening arguments Wednesday in her second-degree murder trial in Brattleboro criminal court.

It isn’t completely clear that Nita Lowery’s fatal case of hypoglycemic shock came from insulin, defense attorney Daniel Sedon said. He claimed the diagnosis was made prematurely in the emergency room at Brattleboro Memorial Hospital because something other than insulin could have produced hypoglycemic shock. That diagnosis colored the state’s lengthy investigation, he said.

Lowery had never used insulin before, the state has said.

LaClaire, 39, formerly of Bennington, N.H., has pleaded innocent to second-degree murder, one count of elder abuse and seven counts of financially exploiting a vulnerable adult.

Sedon did his best to plant the seeds of reasonable doubt in the minds of the 16 jurors (including four alternates) hearing the murder case, which is expected to hear from conflicting medical experts from England and Canada. The trial is expected to take three weeks.

Assistant Attorney General Matthew Levine said that “somehow Nita Lowery had been given insulin” which put her into a coma from which she never recovered on April 1, 2009.

Levine admitted that initially Lowery’s death had been “something of a mystery,” but that medical experts had uncovered the cause. And the discovery that someone was using her credit card to steal $4,000 answered the question of why it happened, he said.

LaClaire was the only nursing assistant on duty the morning Lowery collapsed, Levine said.

Sedon said while LaClaire did have financial problems, other people had access to Lowery’s credit card, and that someone beside LaClaire stole $30,000 in gold jewelry from the safe in Lowery’s room at the Thompson House in the months before her death.

LaClaire didn’t steal Lowery’s jewelry, he argued, because she wouldn’t have let her vehicle be repossessed in the months after the theft, which was never solved by Brattleboro Police.

LaClaire has been portrayed by the state as a financially strapped nursing assistant who used her own insulin to inject Lowery and an hour later used Lowery’s credit card to withdraw large sums of cash from an ATM.

But Sedon told the 10-woman, six-man jury, in a trial overseen by Judge David Suntag, that Lowery’s grandson and his former girlfriend spent lots of time with Lowery at her room at Thompson House.

Sedon said Nita Lowery adored her grandson, John A. Lowery IV, but didn’t care for his girlfriend, and Thompson House staff had reprimanded the couple for taking a shower together in the basement of the nursing facility. The couple lived two blocks away, he said.

Sedon said the girlfriend died in Burlington “in the gutter of chronic alcohol abuse.”

In fact, Sedon said, it’s not even clear that Lowery was the victim of a homicide. He noted that it took the state more than three years of intense investigation to bring charges against his client.

Lowery’s death certificate still lists her manner of death as “undetermined,” he said.

Sedon said Lowery’s politically well-connected family — her late husband John Lowery Jr., was a former district court judge — put pressure on then-Gov. James Douglas and the Vermont attorney general’s office to bring charges in connection with her death. Lowery was related to the locally well-known Speno and Corbeil families, Sedon said, and counted former Gov. Thomas Salmon as a close friend.

The first seeds of doubt about Lowery’s death were planted by a Brattleboro doctor, he said, with no evidence that Lowery had been injected with insulin other than she had endured severe hypoglycemia.

Sedon, who had given the jurors little clue what LaClaire’s defense would be until Wednesday, promised the jury “more facts” would be presented during the course of the trial.

Sedon said Lowery was “larger than life” to her extended family in Brattleboro, and was beloved by many of the staff at Thompson House. In earlier years, Lowery was a secretary to the president of Windham College, and legal secretary to Brattleboro attorney Charles “Chuck” Cummings, now retired, who attended the trial Wednesday.

But Sedon said Lowery had many medical problems, was a cancer survivor, a stroke victim, a smoker and had an undiagnosed lung tumor at the time of her death. She used a wheelchair since she couldn’t walk safely.

Lowery’s only daughter, Gail LaHaise of Walpole, N.H., was the first witness at the trial. She said her mother moved into Thompson House after her recovery from a 2001 stroke put too much stress on her and her family.

LaHaise, a retired Bellows Falls reading teacher, said her mother didn’t like living at Thompson House, but she was active in many ways, including working with Sen. Bernard Sanders to get a Veterans Administration clinic in Brattleboro.

She was very fond of her grandson, John Lowery IV, and spent a lot of time with him. John Lowery, an Iraq War vet, who was attending community college, had spent hours studying in his grandmother’s room, she said.

LaHaise, who frequently wiped away tears at the memory of her mother’s death, said her mother kept her credit card in her pursue in a locked cabinet in her room. While Lowery wore a lot of her “bling,” she said with a smile, she kept a lot of her jewelry in a safe inside her locked closet.

LaHaise said her mother also kept her room locked at Thompson House, and kept all the keys on a bracelet.

LaHaise said her mother had a computer, but never accessed her financial records, including her credit card, via the computer, which she used primarily for email and research.

“I’m not sure she could Google,” LaHaise said of her mother.

The state has said that in the hour before Lowery was found comatose in her room, someone used her computer and personal telephone to access her credit card company and set up a PIN number for the first time.

Within the hour, someone went to a bank ATM in downtown Brattleboro and withdrew $503, Levine, the prosecutor, said.

Other witnesses Wednesday included the other licensed nurse assistants who tended to Lowery during her eight years at Thompson House.

Both nursing assistants cried in describing Lowery, who they said they had loved.

“She was very outgoing, a dynamic person,” said nursing assistant Sarah Delano. “She was full of life.”